Dose-escalating Safety and Preliminary Efficacy of DaxibotulinumtoxinA for Injection in Cervical Dystonia

This is an open-label, dose-escalation study to assess the safety and preliminary efficacy of daxibotulinumtoxinA in subjects with isolated cervical dystonia (CD).

Inclusion Criteria:

• Meets diagnostic criteria for isolated cervical dystonia
• Has moderate severity with a baseline Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) - Total score of at least 20 and a TWSTRS-Severity subscale score or at least 15
• Has been using stable doses of focal dystonia medications for at least 3 months and willing to continue through end of study

Exclusion Criteria:

• Cervical dystonia attributable to an underlying etiology, such as traumatic torticollis or tardive torticollis; predominant retrocollis or anterocollis cervical dystonia
• Significant dystonia in other body areas, or is currently being treated with botulinum toxin for dystonia in other areas than isolated cervical dystonia
• Neurological abnormalities other than cervical dystonia
• History of severe dysphagia or aspiration, or current clinically significant swallowing disorder
• Previous neck surgery, phenol injection to the neck muscles, myotomy or denervation surgery in the neck/shoulder region, or intrathecal baclofen
• Marked limitation on passive range of motion that suggests contractures or other structural abnormality, e.g. cervical contractures or cervical spinal deformity
• Profound atrophy of cervical musculature
• Any neurological condition that may place the subject at increased risk with exposure to botulinum toxin type A, including peripheral motor neuropathic diseases such as amyotrophic lateral sclerosis and motor neuropathy, and neuromuscular junctional disorders such as Lambert-Eaton syndrome and myasthenia gravis
• Suboptimal efficacy response to any prior botulinum toxin type A product, when a previous treatment produced more optimal therapeutic response, as judged subjectively by the Investigator
• Previous treatment with any botulinum toxin product for any condition within the 6 months prior to Screening and during the study; presence of any blood coagulation disorder; or on anticoagulation treatment with international normalized ratio (INR) > 3.5